Granular gases are convenient model systems to investigate the statistical physics of nonequilibrium systems. In the literature, one finds numerous theoretical predictions, but only few experiments. We study a weakly excited dilute gas of rods, confined in a cuboid container in microgravity during a suborbital rocket flight. With respect to a gas of spherical grains at comparable filling fraction, the mean free path is considerably reduced. This guarantees a dominance of grain-grain collisions over grain-wall collisions. No clustering was observed, unlike in similar experiments with spherical grains. Rod positions and orientations were determined and tracked. Translational and rotational velocity distributions are non-Gaussian. Equipartition of kinetic energy between translations and rotations is violated.
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http://dx.doi.org/10.1103/PhysRevLett.110.144102 | DOI Listing |
J Environ Manage
January 2025
Department of Environmental Science and Engineering, Zhejiang Ocean University, No.1 Haida South Road, Zhoushan, 316022, PR China; Zhejiang Provincial Key Laboratory of Petrochemical Environmental Pollution Control, Zhoushan, 316022, PR China. Electronic address:
In order to study the resistance mechanisms of biofilm and granular sludge to various dissolved oxygen (DO) exposures in anaerobic ammonium oxidation (anammox) process, a biofilm - granular sludge anammox reactor was established and operated. Experimental results showed that DO levels of ≤0.41 mg L hardly affected the total nitrogen removal efficiency (TNRE).
View Article and Find Full Text PDFJ Environ Manage
January 2025
Department of Water and Wastewater Engineering, School of Urban Construction, Wuhan University of Science and Technology, Wuhan, 430065, China. Electronic address:
The microalgal-bacterial granular sludge (MBGS) process shows potential for carbon-neutral wastewater treatment, yet its application in wastewater treatment plants remains underexplored. This study attempted to use a continuous-flow raceway reactor to treat real municipal wastewater using the MBGS process. The results showed that the removal efficiencies of organics peaked on the fifth day, while declining trends were observed for nitrogen and phosphorus removal.
View Article and Find Full Text PDFJ Environ Manage
January 2025
Institute of Pollution Control and Environmental Health, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, 300401, China.
The new-type submerged granular sludge membrane bioreactor (S-GSMBR) was constructed by installing a membrane module inside an upflow anaerobic sludge blanket. S-GSMBR achieved the fast start-up (47 d) and long-term stable operation (133 d) of mainstream Anammox process as well as the effective control of membrane fouling. The maximum nitrogen removal rate and efficiency were 0.
View Article and Find Full Text PDFChemosphere
February 2025
University of Washington, Mechanical Engineering Department, Seattle, WA, 98195, USA. Electronic address:
Granular activated carbon (GAC) is widely used to treat contaminated per- and polyfluoroalkyl substances (PFAS) waste streams, resulting in the accumulation of large quantities of spent GAC that need to be landfilled or regenerated. A novel modified supercritical CO (scCO) extraction for regeneration of spent GAC is developed. With the addition of organic solvents and acid modifiers, the procedure yielded >99% perfluorooctanoic acid (PFOA) desorption after a 60-min treatment in a continuous flow reactor.
View Article and Find Full Text PDFJ Environ Manage
January 2025
Key Laboratory of Urban Storm Water System and Water Environment Ministry of Education, Beijing University of Civil Engineering and Architecture, Beijing, 100044, China; Sino-Dutch R&D Centre for Future Wastewater Treatment Technologies/Key Laboratory of Urban Stormwater System and Water Environment, Beijing University of Civil Engineering and Architecture, Beijing, 100044, China.
Excessive organic matter in the anaerobic ammonia oxidation (Anammox) leads to the growth of a large number of heterotrophic bacteria, which disrupts the anaerobic ammonia oxidation. The adsorption-anaerobic ammonia oxidation process can effectively reduce excessive organic matter, capturing it instead of consuming it, which is a sustainable development technology. In this study, utilizing the excellent adsorption performance of aerobic granular sludge (AGS), an adsorption-regeneration process was employed to remove organic matter at the front end of the Anammox process through bio-adsorption in an artificial simulated domestic sewage environment, and it was successfully used for denitrification.
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